Overview
ESR is the distance erythrocytes fall in a vertical column of anticoagulated blood in a defined time (classically 1 hour, Westergren).
Clinical Importance
Nonspecific marker of inflammation or disease activity when clinically requested
Selected monitoring pathways that still specify ESR
Specimen Requirements
Collection depends on method. ICSH Westergren uses citrate-diluted blood; many automated analyzers accept EDTA. Always follow the laboratory's stated tube type.
- ICSH Westergren reference method: blood diluted in sodium citrate
- Many automated ESR systems are validated for EDTA whole blood; follow the performing laboratory instructions
- Mix well; exclude clots; test within method-specific stability limits
Analytical Method
Rouleaux formation and plasma protein composition (acute-phase proteins) accelerate settling; hematocrit also strongly influences ESR.
Instruments Used
Automated analyzers
- Automated ESR analyzers using Westergren-based or alternate photometric settling methods
Manual methods
- Manual Westergren pipette method (ICSH reference framework)
Reference Values
Typical adult SI examples below follow widely published international hematology practice (e.g., Dacie and Lewis; Henry's). Always interpret against the method- and demographics-specific interval printed on the patient report (CLSI EP28-A3c). Neonatal, pediatric, pregnancy, and altitude intervals differ.
ESR rises with age and is generally higher in women than men.
Many laboratories use age-adjusted upper limits (commonly cited Miller-type formulas: men ≈ age/2; women ≈ (age + 10)/2, in mm/h); verify the local formula and method.
Typical published younger-adult Westergren upper limits are often near <15 mm/h (men) and <20 mm/h (women) before age adjustment.
Pregnancy increases ESR.
Interpretation
Common Causes of Increased Results
- Elevated ESR is nonspecific; inflammation, anemia, paraproteins, and technical factors can all raise ESR
Common Causes of Decreased Results
- Very low ESR may occur with polycythemia, extreme leukocytosis, or technical issues; interpret cautiously
Clinical Significance
- Nonspecific inflammation adjunct
- Selected disease-activity monitoring when ESR is protocol-specified
Factors Affecting Results
Pre-analytical
- Wrong anticoagulant/dilution, clot, or delayed testing
- Extreme ambient temperature
Analytical
- Tube not vertical; vibration; bubbles
- Method differences (manual Westergren vs alternate technologies)
Post-analytical
- Treating ESR as a disease-specific diagnostic test
Advantages and Limitations
Advantages
- Inexpensive, widely available inflammation adjunct
- ICSH guidance supports Westergren standardization
Limitations
- Nonspecific; strongly affected by anemia and plasma proteins
- Often less useful than CRP for acute decisions
Clinical Pearls
ESR is supportive laboratory noise without clinical context; never treat it as a stand-alone diagnosis.
References
Authoritative textbooks, guidelines, and reviews supporting this laboratory test reference. Verify reference intervals, critical limits, and method details against institutional protocols and current guideline editions.
Textbooks
- McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Elsevier; 2021.
- Rodak BF, Carr JH. Rodak's Hematology: Clinical Principles and Applications. 6th ed. Elsevier; 2020.
- Hoffbrand AV, Moss PAH, Pettit JE. Essential Haematology. 8th ed. Wiley-Blackwell; 2019.
- McKenzie SB, Williams JL. Clinical Laboratory Hematology. 4th ed. Pearson; 2022.
- Bain BJ, Bates I, Laffan MA. Dacie and Lewis Practical Haematology. 12th ed. Elsevier; 2017.
- Kaushansky K, et al. Williams Hematology. 10th ed. McGraw-Hill; 2021.
- Bain BJ, Bates I, Laffan MA. Dacie and Lewis Practical Haematology. 12th ed. Elsevier; 2017.
CLSI and Professional Guidelines
- Clinical and Laboratory Standards Institute. Validation, Verification, and Quality Assurance of Automated Hematology Analyzers; Approved Standard. CLSI document H26-A2. CLSI; 2010.
- Clinical and Laboratory Standards Institute. Reference Leukocyte (WBC) Differential Count (Proportional) and Evaluation of Instrumental Methods; Approved Standard. CLSI document H20-A2. CLSI; 2007.
- Clinical and Laboratory Standards Institute. Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory; Approved Standard. CLSI document EP28-A3c. CLSI; 2010.
- Clinical and Laboratory Standards Institute. Management of Critical- and Significant-Risk Results. CLSI guideline GP47-Ed1. CLSI; 2015.
- International Council for Standardization in Haematology. ICSH recommendations for measurement of erythrocyte sedimentation rate. Int J Lab Hematol. 2011;33(5):458–466.
Frequently Asked Questions
Common questions about using this Erythrocyte Sedimentation Rate (ESR) laboratory test Medical Laboratory Library reference in Medical Laboratory Science education.
What is the Erythrocyte Sedimentation Rate (ESR) laboratory test reference used for?
This Medical Laboratory Library page summarizes the clinical importance of Erythrocyte Sedimentation Rate (ESR). Review the Clinical Importance section for why the test is ordered in laboratory medicine practice.
Where can I find Erythrocyte Sedimentation Rate (ESR) specimen requirements?
See the Specimen Requirements section on this page for specimen information related to Erythrocyte Sedimentation Rate (ESR). Confirm collection details against your laboratory protocol.
Where are Erythrocyte Sedimentation Rate (ESR) reference values listed?
See the Reference Values section on this Laboratory Library page. Reference ranges can vary by method and population, so verify intervals with your laboratory.
How do I interpret Erythrocyte Sedimentation Rate (ESR) results?
Use the Interpretation section for laboratory interpretation framing, including increased and decreased result patterns when provided. Do not treat educational text as a patient-specific diagnosis.
What analytical method is used for Erythrocyte Sedimentation Rate (ESR)?
See the Analytical Method section for principle and method notes. Method details may differ by instrument and institutional SOP.
Are related laboratory tests linked from Erythrocyte Sedimentation Rate (ESR)?
Yes. The Related Laboratory Tests section lists connected references for continued lookup in the Medical Laboratory Library.
How can I continue learning after reading Erythrocyte Sedimentation Rate (ESR)?
Use Continue learning links on this page for related Academy lessons, medical laboratory quizzes, or laboratory case studies when available for this Hematology topic.
What are the clinical pearls for Erythrocyte Sedimentation Rate (ESR)?
See the Clinical Pearls section for concise laboratory practice notes associated with Erythrocyte Sedimentation Rate (ESR). Apply pearls alongside institutional protocols.
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